It has been reported that the expression levels of CRAC channel proteins, Orai1 and STIM1, were found to be relatively low in the normal pancreatic ductal epithelial cells when compared to several PDAC cell lines, suggesting that cancer cells probably upregulate Orai1 and STIM1 in order to save themselves from undergoing apoptosis [14]. This evidence concerns the gene STIM1 and cancer.